遮荫对10种地被植物光合特性的影响

为了探讨地被植物在不同遮荫条件下的适应性,本研究以10种地被植物为材料,对其在不同光照条件下的生长状态、日平均净光合速率、表观量子效率及光补偿点进行分析.结果表明:遮荫水平对10种植物的光合有很大影响,10种植物能忍受的遮荫程度不同.对旋覆花、甘野菊、大叶铁线莲、青杞、委陵菜来说,全光比较合适；对蛇莓、匍枝毛茛、匍枝委...     

NaCl胁迫对羽衣甘蓝生理生化指标的影响

试验采用水培种植的方法研究不同NaCl浓度对羽衣甘蓝幼苗光合色素含量、可溶性蛋白质含量、过氧化氢酶(CAT)活性以及过氧化物酶(POD)活性的影响。结果表明:随着NaCl浓度的增加,叶绿素含量总体呈下降趋势;可溶性蛋白质含量、CAT和POD活性随着NaCl浓度的增加先上升后下降;在NaCl浓度为600mmol/L时可溶性蛋白质含量、CAT活性达到最高值,而POD活性则是在NaCl浓度为800mmol/L时达到最高。     

Strawberry Production in Central Europe

Abstract

This paper focuses on the cropping systems in central European countries such as Belgium, The Netherlands, UK, Ireland, Germany, Switzerland and the northern part of France and Italy. During the last decade there has been a consistent increase in programmed “out-of-season” strawberry production in several central European countries. This is being achieved in part, by using cultivars with different cropping seasons, but mainly by sequential planting of cold-stored plants and by growing strawberries in greenhouses and plastic tunnels. These methods have made it possible to extend the strawberry production for 11 months, from the end of February until mid January in central European countries with moderate climates.     

A survey of antimicrobial resistance in Escherichia coli isolated from wild sika deer (Cervus nippon) in Japan

We examined the antimicrobial susceptibility of 848 Escherichia coli isolates from 237 feces samples of wild sika deer (Cervus nippon) captured between 2016 and 2019 in 39 of the 47 prefectures of Japan. Five of the 237 wild sika deer (2.1%) carried E. coli with resistance to at least one antimicrobial, and all the resistant isolates showed resistance to tetracycline. The resistant isolates contained antimicrobial resistance genes that were similar to those in E. coli derived from humans and farm animals. Although wild sika deer are not currently likely to be a source for the transmission of antimicrobial resistance in Japan, they can potentially mediate antimicrobial resistance spread by coming into contact with humans, animals, and their surroundings.     

Pseudorabies virus infection in hunting dogs in Oita,Japan: Report from a prefecture free from Aujeszky’s disease in domestic pigs

We isolated two pseudorabies virus (PRV) isolates (designated OT-1 and OT-2) from two hunting dogs exhibiting neurological manifestations after eating the flesh of wild boar hunted in Oita prefecture, Kyushu Island, Japan. The isolates corresponded to a previously reported PRV (MY-1 strain) isolated from a hunting dog in neighboring Miyazaki prefecture, and it clustered into genotype II based on the glycoprotein C sequence. Our results suggest that this common PRV strain may have been maintained in wild boars on Kyushu Island even though domestic pigs in this area have attained an Aujeszky’s disease-free status.     

HPLC法测定天然植物粗提物中芍药苷含量

建立高效液相色谱法检测天然植物粗提物饲料原料中芍药苷的测定方法。用十八烷基硅烷键合硅胶色谱柱,以乙腈-0.1%磷酸溶液(14:86)为流动相,检测波长230nm,流速：1.0 mL/min;柱温：30 ℃;进样量：10μL。结果显示,芍药苷的线性方程为Y=10.6017X－14.8514,(r=0.99966,n=6),本方法的回收率为100.4~102.1%,RSD均小于2.0%。结果表明,本方法准确,可靠,适用于天然植物粗提物饲料原料中芍药苷的测定。     

贵州锰矿废渣堆场重金属污染风险评价及草本植物重金属吸收特征

为明确锰矿废渣堆场重金属污染及优势草本植物重金属吸收特征,对贵州省典型锰矿废渣堆场的重金属污染风险进行了评价,并调查研究了锰矿废渣堆场草本植物的类群及重金属吸收特征。共采集优势草本植物18种,隶属11科18属,菊科和禾本科为优势科。对18种草本植物体地上部、地下部及其生长基质中Cr、Ni、Cu、Zn、Cd、Pb和Mn 7种重金属元素进行了测定,结果显示,锰矿废渣堆场重金属污染空间变异较大,Mn污染最严重,其次是Cd,属于Mn、Cd复合型污染。计算了草本植物对7种重金属元素的富集系数、转运系数,并对18种草本植物进行了聚类分析,综合分析了草本植物重金属吸收特征,结果显示,看麦娘对Cd富集系数达22.49,对Cd有较强的富集能力;五节芒、商陆对Cr、Ni具有较强的富集能力和转运能力;风毛菊和夏枯草对锰矿废渣区多种重金属均表现出较强的富集能力和转运能力。研究结果表明,锰矿废渣堆场主要为Mn和Cd污染,矿区本土自然生长的优势草本植物可作为生态修复的首选植物。     

Effect of Prosopis (mesquite) invasion and clearing on vegetation cover in semi-arid Nama Karoo rangeland,South Africa

The Nama-Karoo is the largest of the three biomes that comprise the semi-arid Karoo-Namib ecoregion of southern Africa. Large tracts of Nama-Karoo rangeland have been invaded by alien leguminous trees of the genus Prosopis. We assessed the impact of Prosopis invasion and clearing on vegetation cover in heavily grazed Nama-Karoo rangeland on two sheep farms in the Beaufort West district of the Western Cape province of South Africa. Our results suggest that, below critical threshold cover levels, Prosopis trees do not affect indigenous vegetation and add to overall rangeland vegetation cover. However, once Prosopis cover exceeds critical thresholds, the trees begin to negatively impact on indigenous vegetation (especially grasses) and overall vegetation cover. In addition, our data suggest that vegetation cover recovers after Prosopis clearing, being temporarily higher than pre-invasion levels possibly as a result of enhanced post-invasion soil fertility. Lastly, our results suggest that Prosopis trees reduce rangeland erosion potential at low cover and increase it after they exceed critical threshold cover. Information about thresholds of Prosopis impact can be used to direct clearing efforts for maximum benefit when resources are limited.     

Habitat use and home range of black-backed jackals (Canis mesomelas) on farmlands in the Midlands of KwaZulu-Natal,South Africa

Black-backed jackals (Canis mesomelas) are an abundant mesopredator on farmlands (croplands and rangelands) across South Africa. Given their adaptability in a changing anthropogenic landscape, knowledge of spatial movements can provide important ecological information on the species. We captured, collared and monitored five black-backed jackals in the Midlands of KwaZulu-Natal to determine their home range and habitat use in farmlands. The 95% fixed kernel (95% FK) home range sizes were large, showing a marked seasonal variation in movement. One adult male dispersed 150?km over two seasons (winter and spring) and thereafter settled into a home range that it maintained. Transient home ranges of males and juveniles were larger than resident home ranges. The mean resident home ranges (95% FK) across seasons for adult males, adult female and juvenile males were 11.4 ± 4.3 km², 5.6 ± 0.36?km² and 2.15 ± 0.45?km², respectively. The mean transient home ranges (95% FK) of all the seasons for adult and juvenile males were 1 181.93 ± 575.81 km² and 104.27 ± 35.64?km², respectively. Adult jackal preferred croplands in spring, summer and autumn but avoided croplands in winter. Variable habitat use and large home ranges in our study confirmed the species’ ability to adapt to agricultural areas.     

Evaluation of truncated LipL32 expressed by Escherichia coli and Pichia pastoris for serodiagnosis of Leptospira infection in rodents

The applicability of the recombinant LipL32 for serodiagnosis of leptospiral infection in field rodents was assessed in this study. An immunodominant region of LipL32 was determined by monoclonal antibodies, and then, truncated LipL32 (tLipL32) was designed to contain the region (87–188th amino acid). The tLipL32 was compared between two recombinant expression hosts Escherichia coli and Pichia pastoris in ELISA. With field rat sera, tLipL32 expressed by P. pastoris (tLipL32p) had high antigenicity without background reactions, while tLipL32 expressed by E. coli (tLipL32e) showed high background reactions, which were reduced by pre-adsorption of sera with E. coli. To evaluate tLipL32-ELISA, field rat sera were tentatively divided into a Leptospira infection positive (12 sera) and a negative group (12 sera) based on the results from flaB gene PCR of kidney samples and WB with whole Leptospira cell. Consequently, the sensitivity of tLipL32p-ELISA for field rat sera was 83% . A similar result was obtained from tLipL32e-ELISA with adsorbed sera, (92%). However, sensitivity of tLipL32e-ELISA using sera without an adsorption treatment was 50%. Regardless of the expression host, tLipL32-ELISA had 100% specificity and sensitivity in experimentally infected laboratory rats. These results suggest that recombinant LipL32 expressed by P. pastoris is more applicable for serodiagnosis in field rats due to a lack of background reaction.